Heating element for eliminating ice from a roof



April 14, 1964 F. N. GLASS ETAL 3,129,316

HEATING ELEMENT FOR ELIMINATING ICE FROM A ROOF Filed July 30, 1962 2Sheets-Sheet 1 4 Cmrnf {Arms 10 lab/I Int WAR/V/A G FERRIS N. GLASSLLOYD J. KREISER .INVEN'TORS Alba.

April 1 1964 F. N. GLASS ETAL HEATING ELEMENT FOR ELIMINATING ICE FROM AROOF Filed July 50, 1962 2 Sheets-Sheet 2 FERRl-S N. GLASS J. KREISERINVENTORS LLOYD United States Patent 3,129,316 HEATING ELEMENT FORELIMINATING ICE FROM A ROOF Ferris N. Glass, 4100 Park Lane Road, andLloyd J.

Kreiser, 2650 Holiday Hills Road, both of Traverse City, Mich.

Filed July 30, 1962, Ser. No. 213,182 1 Claim. (Cl. 219--19) The presentinvention is associated with conventional overlaid roof construction,and provides a heating element which can be interposed between theoverlaid conventional elements. The fastenings normally used to securethese conventional elements are also used to secure the heating elementin position, with the standard location or the fastenings beingmaintained. Normally these heating devices will be disposed along theeave portion of the building, as it is here that the formation of icebegins to develop to a suflicient extent to cause water to back upunderneath the shingles and enter the building. It is by no means new tomount a heating element in this area, as it has been common practice tostretch a length of electrical resistance wire along an eave trough, oradjacent to it. The principal features of the present invention centerin the arrangement which is readily structurally incorporated in thestandard overlaid roofing assembly, and which results in the uniformdistribution of heat over a considerable area. The several features ofthe invention will be analyzed in further detail through a discussion ofthe particular embodiments illustrated in the accompanying drawings. Inthe drawings:

FIGURE 1 presents a perspective view of a complete heating unit, showingthe normally uppermost side with the usual markings for assisting theworkman on installation.

FIGURE 2 is a perspective view of the under side of the unitshown inFIGURE 1, with a portion of the cover removed to expose the insulatedheating element.

FIGURE 3 is a section on an enlarged scale on the plane IIIIII of FIGURE2.

FIGURE 4 illustrates a connecting strip usable on interconnecting aseries of the heating units shown in FIG- URE 1.

FIGURE 5 is a sectional elevation at a point of junction betweensuccessive heating elements.

FIGURE 6 is an expanded view showing the overlaid structure of the roofat the eave, and illustrating the man ner in which the heating unit isinterposed between the standard roof elements.

A heating unit embodying the preferred form of this invention isillustrated in FIGURES 1, 2, and 3. This device includes an aluminumsheet 10 of a thickness and hardness selected to receive nails manuallydriven through it without pre-drilling. Ordinary cold-rolled aluminumsheet stock of low alloy content, and of approximately thousandths of aninch in thickness, will serve very efiectively. Nails can easily bedriven through this thickness, and it can be bent readily to a fairlysharp radius without cracking. The material of the sheet 10 should be ofhigh thermal conductivity, and aluminum seems to be the mostsatisfactory for this purpose. Copper would also be acceptable, but thecost is normally somewhat greater.

A length of insulated resistence wire 11 is preferably adhesivelysecured to the panel 10 along a serpentine path as shown in FIGURE 2. Alayer of adhesive as indicated at 12 may be applied generally to thecentral portion of the sheet 10, with the heating element laid inposition on it, after being pre-formed into the desired configuration.It is important that the marginal area shown at 13 be left clear alongits full length, as nails will ultimately be driven through this area tosecure the heating unit in position. Even though the resistance wire 11does not extend throughout the sheet 10 (because of the unoccupiedmarginal area), the thermal transmission of the aluminum will deliverthe heat out over the full area of the sheet 10 at a fairly uniformintensity. The amount of voltage supplied to the heating element 11 willvary with the length of it, and also with the amount of heat that itbecomes necessary to supply to a particular installation in order tomaintain the roof free of ice formations.

To complete the structure of the heating element itself, it ispreferable to incorporate a sheet of foil or some heat-resistantmaterial as a cover 14, this cover being secured adhesively to the sheet10 with the heating element interposed between the cover and the sheet.The same adhesive which secures the cover in position may also bond theheating element, or the cover may be bonded in selected locations sothat the cover itself holds the heating element in place.

FIGURES 4 and 5 show an arrangement for connecting a series of theseheating units for installation along a long stretch of roof. Thisparticular form of interconnection is well known in the sheet metal art,and is based upon the connector 15 shown in FIGURE 4, with the centralportion formed to the cross section illustrated in FIGURE 5. The reversebends 16 and 17 on the units 18 and 19, respectively, may beinterengaged with the strip 15 to structurally connect these as shown.With the strip 15 formed of thermally conductive material, the heattransfer across this junction is accomplished with acceptableefficiency. The element 18 may even be a mere extension sheet ofaluminum without incorporating an electrical resistance element. In thismanner, an area of somewhat less heat intensity may be provided wherethe heat requirements are somewhat decreased.

Referring to FIGURE 6, the cave structure illustrated in this viewincludes a substructure generally indicated at 20, which usually iscomposed of rough boards. Roofing paper 21 is normally overlaid overthis substructure, and the heating element 22 may be laid directly ontop of this roofing paper. Separate fastenings as shown at 23 may beused to hold this heating element in position, and the edge oppositefrom these fastenings may be turned over as shown at 24 to embrace theedge of the cave as shown. Separate fastenings as shown at 25 and 26 maybe incorporated at this edge bend. A heating unit disposed further upthe roof would not be formed in this manner, this portion simply beingleft flat. Shingle layers as shown at 27 and 28 are then overlaid uponthe heating element 22, with the fastenings normally used to securethese in position traversing the same general marginal area 13 as thefastenings 23.

In the modification shown in FIGURE 6, the ends of the heating wire 11are brought together at a junction box 29 mounted on the sheet 11 andengaging a hole in the substructure 20, and serving as a terminal forthe conduit 30. The ends 31 and 32 of the indicated element 11 aresuitably interconnected with conventional circuit wiring (not shown) toa source of electric potential. In the arrangement shown in FIGURE 1, aconnector 33 is incorporated in the heating unit, and this connectorwould normally be disposed opposite a hold in the substructure toperform a function similar to that of the box 29.

The particular embodiments of the present invention which have beenillustrated and discussed herein are for illustrative purposes only andare not to be considered as a limitation upon the scope of the appendedclaim. In this claim, it is our intent to claim the entire inventiondisclosed herein, except as we are limited by the prior art.

We claim:

In combination with the cave portion of a roofing asr 4 sembly whichincludes overlapped covering pieces of circuit means supplying anelectric potential to said standard Width secured in position byparallel rows of heating element, nails, said eave portion having a holetraversing the subsaid circuit means including connector meansdisstructure thereof, a heating device comprising: posed opposite saidhole; and

a sheet of aluminum of substantial thickness and a 5 a foil cover forsaid heating element, said cover being hardness selected to accept nailsdriven through the secured to said sheet, and said heating elementbesame; ing interposed between said cover and said sheet. an insulatedelectric resistance heating element secured to the underside of saidsheet'throughout the length References Clted m the file of thls patentof said element along a serpentine path, said sheet 10 UNITED STATESPATENTS having continuous opposite marginal portions unoc- 2,507,039Miner May 9 1950 cupied by said heating element and disposed to re-2,546,743 Harrison Mar. 27, 1951 ceive said nails, said heating elementbeing disposed 2,932,711 Adams 12, 0 i the pa between said rows ofnails, 3,010,007 Theodore et a1 21, 6

said marginal portions being marked on said sheet; 5 3,022,412 W t b 20,1962

